Question for Immunology brainiacs?

So, I am currently taking a course in Micro and we are covering the raw basics of the immune system. Today in lecture we learned how "pain" is caused by the destruction of RBC's which subsequently release bradykinins, prostaglandins, etc., which lower the pain threshold. Does this mean that if RBC's did not release these pain factors, even thought they were destroyed, that we would technically not feel pain? In other words, is it purely the release of these proteins that causes what we perceive as pain rather than the injury itself?